The scene is the battlefield at Kurukshetra, where two armies have arrived as a result of a dynastic struggle. Several Aryan tribes from across India have made alliances with either of the sides. One, is the side of the Pandavas, who were dishonoured and exiled from their kingdom by their rivals, the Kauravas, and have now come back, completing their exile to take back their Kingdom. The Pandavas have declared Dharmayuddha, or religious war, as a means to end Kaurava hegemony of the Kingdom of Kuru.
At the center of the battlefield are Arjuna and Krishna. Arjuna is the archer, and Krishna is his charioteer. The Pandava army is commanded by the Prince of Panchala, Drupad, while the Kaurava army is commanded by Grandsire Bhishma, the defence minister of the Kuru Kingdom. Duryodhana is the Kaurava prince, and is the central villain of the conflict, his father is Dhritrashtra the Blind, the helpless Emperor of the Kurus lost in the affection for his immoral son.
Sanjay, the advisor to Dhritrashtra is able to see the scene at the battlefield with his divine powers despite being at the fort miles away, and tells the developments at Kurukshetra to Dhritrashtra.
Arjun asks Krishna to lead the chariot to the centre of the battlefield, for one last time, he wishes to see his kinsmen who now stand against him. On seeing the might of the Kaurava and Pandava armies, fear consumes him, and he falls to the ground, begging Krishna to not let him wage this holy war, it is here at this very moment, that Krishna reveals himself as the Lord, and encourages him to stand up and fight not for himself but for Dharma. This is where the Gita begins.